TGFβ upregulates PAR-1 expression and signalling responses in A549 lung adenocarcinoma cells

The major high-affinity thrombin receptor, proteinase activated receptor-1 (PAR-1) is expressed at low levels by the normal epithelium but is upregulated in many types of cancer, including lung cancer. The thrombin-PAR-1 signalling axis contributes to the activation of latent TGFβ in response to tissue injury via an avβ6 integrin-mediated mechanism. TGFβ is a pleiotropic cytokine that acts as a tumour suppressor in normal and dysplastic cells but switches into a tumour promoter in advanced tumours. In this study we demonstrate that TGFβ is a positive regulator of PAR-1 expression in A549 lung adenocarcinoma cells, which in turn increases the sensitivity of these cells to thrombin signalling. We further demonstrate that this effect is Smad3-, ERK1/2-and Sp1-dependent. We also show that TGFβ-mediated PAR-1 upregulation is accompanied by increased expression of integrin av and β6 subunits. Finally, TGFβ pre-stimulation promotes increased migratory potential of A549 to thrombin. These data have important implications for our understanding of the interplay between coagulation and TGFβ signalling responses in lung cancer

Experimental Granulomatous Pulmonary Nocardiosis in BALB/C Mice

Pulmonary nocardiosis is a granulomatous disease with high mortality that affects both immunosuppressed and immunocompetent patients. The mechanisms leading to the establishment and progression of the infection are currently unknown. An animal model to study these mechanisms is sorely needed. We report the first in vivo model of granulomatous pulmonary nocardiosis that closely resembles human pathology. BALB/c mice infected intranasally with two different doses of GFP-expressing Nocardia brasiliensis ATCC700358 (NbGFP), develop weight loss and pulmonary granulomas. Mice infected with 109 CFUs progressed towards death within a week while mice infected with 108 CFUs died after five to six months. Histological examination of the lungs revealed that both the higher and lower doses of NbGFP induced granulomas with NbGFP clearly identifiable at the center of the lesions. Mice exposed to 108 CFUs and subsequently to 109 CFUs were not protected against disease severity but had less granulomas suggesting some degree of protection. Attempts to identify a cellular target for the infection were unsuccessful but we found that bacterial microcolonies in the suspension used to infect mice were responsible for the establishment of the disease. Small microcolonies of NbGFP, incompatible with nocardial doubling times starting from unicellular organisms, were identified in the lung as early as six hours after infection. Mice infected with highly purified unicellular preparations of NbGFP did not develop granulomas despite showing weight loss. Finally, intranasal delivery of nocardial microcolonies was enough for mice to develop granulomas with minimal weight loss. Taken together these results show that Nocardia brasiliensis microcolonies are both necessary and sufficient for the development of granulomatous pulmonary nocardiosis in mice

Microscopic bacterial microcolonies are responsible for the formation of granulomas.

<p>A) BALB/c mice (n = 3 per group) received 10⁹ (red) or 10^{9 Highly purified single-cell} (purple) NbGFP CFUs and were weighted daily. B) Lungs from mice in A were analysed at day 4 post infection by whole lung imaging at λ 488 nm. Representative images of two lungs per group are shown. C) BALB/c mice (n = 5 per group) received 10⁹ (red) CFUs or ≈100 (teal) NbGFP microcolonies and were weighted daily. D) Lungs from mice in D were analysed at day 4 post infection by whole lung imaging at λ 488 nm. Representative images of two lungs per group are shown. White arrows point to GFP⁺ lesions. E) Representative histology of lungs in mice receiving 10^{9 Highly purified single-cell} CFUs at day 4 post infection. Kinyoun's stain. F) Representative images of lesions present in mice receiving microcolonies. Kinyoun's stain. Red stained NbGFP is evident at the core of the lesion. G) Representative H&E image of lesions present in mice 21 days after infection with purified microcolonies. White arrows: NbGFP, black arrows: activated macrophages, black arrowheads: lymphocytes.</p

Neither alveolar macrophages nor eosinophils nor neutrophils are targets for NbGFP infection in the lung.

<p>A) Bone marrow derived macrophages (BMDM) or alveolar macrophages (AM) were incubated <i>in vitro</i> with NbGFP (1:10) and imaged at 2 hours and at 48 hrs post infection. Cells from BALF of infected mice were imaged 48 hrs after infection to look for infected alveolar macrophages. Representative images are shown. B) BALF analysis of eosinophils by flow cytometry. Left panel shows non-specific events detected within the eosinophil gate in the absence of CCR3 staining. Right panel shows no increase in GFP+ events amongst eosinophils stained with an anti-CCR3 antibody. C) BALF analysis of granulocytes by flow cytometry at 24 (left panel) and 48 (right panel) hours post infection.</p

NbGFP microcolonies are present in the lungs of infected mice as early as 6 hours post infection.

<p>A) Lungs from mice receiving 10⁹ CFUs were analysed at 6 hours, 1 day and 4 days post infection by whole lung imaging at λ 488 nm. Representative images of two lungs per time point are shown. B) Confocal microscopy images of lung sections at 6 and 24 hours post infection. C) Growth curve of NbGFP under constant stirring to prevent biofilm formation.</p

Interim safety and immunogenicity results from an NDV-based COVID-19 vaccine phase I trial in Mexico

Abstract There is still a need for safe, efficient, and low-cost coronavirus disease 2019 (COVID-19) vaccines that can stop transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Here we evaluated a vaccine candidate based on a live recombinant Newcastle disease virus (NDV) that expresses a stable version of the spike protein in infected cells as well as on the surface of the viral particle (AVX/COVID-12-HEXAPRO, also known as NDV-HXP-S). This vaccine candidate can be grown in embryonated eggs at a low cost, similar to influenza virus vaccines, and it can also be administered intranasally, potentially to induce mucosal immunity. We evaluated this vaccine candidate in prime-boost regimens via intramuscular, intranasal, or intranasal followed by intramuscular routes in an open-label non-randomized non-placebo-controlled phase I clinical trial in Mexico in 91 volunteers. The primary objective of the trial was to assess vaccine safety, and the secondary objective was to determine the immunogenicity of the different vaccine regimens. In the interim analysis reported here, the vaccine was found to be safe, and the higher doses tested were found to be immunogenic when given intramuscularly or intranasally followed by intramuscular administration, providing the basis for further clinical development of the vaccine candidate. The study is registered under ClinicalTrials.gov identifier NCT04871737

Aborto, abandono, y la muerte de Augusta García Platas en Ayacucho, Perú, 1946

Resumen Augusta García Platas murió tras un aborto clandestino en Ayacucho en 1946. Este ensayo, basado en materiales del Archivo Histórico de Ayacucho, da cuenta del proceso criminal que se abrió para determinar los responsables de su muerte. A pesar de que sindicaron a ciertos individuos como culpables directos de provocar el aborto, las autoridades judiciales consideraban que la causa de fondo de la muerte de la joven había sido el abandono por parte de quienes debían velar por su salud física y moral. Este caso nos brinda la oportunidad de esclarecer las estrategias que los implicados usaban para defenderse de acusaciones criminales. Además, nos ayuda a entender las diversas deficiencias del Poder Judicial peruano de mediados del siglo XX